The man with the golden pen

German Pavilion, Expo Montreal, 1967 (with Ralph Gutbrod)

Arguably the world’s top architectural award, the Royal Gold Medal for Architecture, is not won by the latest avant-garde design: it’s more of a lifetime achievement award.

This year’s winner, Frei Otto of Germany, fits the bill. He’s 79 years old and was hailed at his medal presentation last week by RIBA president, George Ferguson, as a hero of his student days in the 1960s.

But just look at those early Otto structures, such as the huge tented pavilion for the Montreal Expo of 1967. This is no quaint relic from the past: it’s a spiky mountain range of fabric that, four decades later, still looks as excitingly futuristic as Zaha Hadid’s latest competition-winner.

No wonder Otto is one of the most popular choices for the gold medal for many years. He virtually invented the modern world of lightweight surface structures, which include not just membrane tents but also grid shells, cable structures, convertible roofs and pneumatics. Their weird and wonderful shapes now regularly erupt in garden pavilions, exhibition halls, shopping centres and even Richard Rogers’ Millennium Dome – and rarely with any loss of visual excitement.

So is Otto an architect or engineer? Though trained as an architect, he claims to be neither, but instead an inventor. Since 1957 he has founded and run two institutes of lightweight structures, with the current one in Stuttgart still going strong. When it comes to actual building projects, he habitually works with consultant engineers and architects, with one of his most constant collaborators being British engineer Buro Happold.

Exhibition Hall, Mannheim, 1975 (with Carlfried Mutschler)

Among Otto’s more notable projects are the vast fabric roof to the Munich Olympic stadium of 1972 and the barrel-vaulted gridshell exhibition hall at Mannheim in 1975. His only permanent building in Britain is at Hooke Park timber craft school in Dorset, designed with architect Ahrends Burton Koralek.

Now that membrane structures have become part of mainstream architecture, Otto has moved on to experiment with new forms and materials. For the roof over the proposed new main station in Stuttgart, he helped devise a series of mushroom-like concrete pedestals with overhead skylights. And for a pedestrian and cycle bridge near Gelshenkirchen in Germany, he came up with a fan-like supports of scaffolding tubes.

Although the naturalistic forms of his structures suggests Otto is a stylist in the romantic German expressionist tradition, he emphatically denies it. One of his most formative experiences, so he claims, was as a prisoner of war after the Second World War, when he had to create buildings out of leftover materials such as steel rails.

It may be light years away from his current European lifestyle, but this hard-knocks experience helped forge a expedient approach of making the best out of limited resources. In a world threatened by global warming, such a sustainable approach has become more vital than ever.